The genus Ameroculodes Bousfield and Chevrier, 1966 is emended to accommodate a new species of oedicerotid amphipod, Ameroculodes miltoni, common to estuarine habitats of the southeastern United States. In this region the new species has been confused with Ameroculodes (=Monocu- lodes) edwardsi (Holmes, 1905) and Deflexilodes (= Monoculodes) intermedius (Shoemaker, 1930), both of which are distinctly larger and endemic to the cold temperate waters of the Northwest Atlantic. Ameroculodes miltoni can be distinguished from A. edwardsi by (1) having the postero-ventral margins of epimeral plates 1-3 rounded, (2) a short, blunt rostrum, (3) uropod 2 with relatively few dorsal spines on the peduncle, (4) and a subovate telson. Deflexilodes intermedius, like A. miltoni, has rounded epimeral plates, but is readily distinguished by the well-developed, elongate dactyls on its 3 rd and 4 th pereopods. Ameroculodes miltoni occurs over a wide range of salinities (<1°/ °° to 35°/ °° ) and is most common in medium to fine sand or sand-silt substrata. It appears to be an important biotic component of northern Gulf of Mexico estuaries.